1. GLAST LAT Project CERN Testbeam WorkShop, Pisa, 20 March 2006 David Smith & Denis Dumora VME DAQ 1 The Bordeaux Data Acquisition system http://ftp.cenbg.in2p3.fr/astropart/Smith/BordeauxDAQnote.pdf Brief history Acquisition computers (VME!) harmonized with User, etc computers Separate topic: the mobilnet. Conclusions

2. GLAST LAT Project CERN Testbeam WorkShop, Pisa, 20 March 2006 David Smith & Denis Dumora VME DAQ 2 History It all started with the CAT Cherenkov telescope… VME detector readout, including GPS and scalers, by U. Paris  Choice of Motorola 64080 based MVME 164 crate controller  « Industry Pack » daughter card to handle event interuppts  Lynx OS (real-time unix-like, now called Lynuxworks) HP workstation for “Master Run Controller” was in LabView!, by E. Polytechnique “rsh” between multiple computers, binary packets zip across ethernet (commands & data) …then there was CELESTE… “Master Run Controller” ported to linux PCs. Explosion in number of 2ndary acquisition and display computers, and in data volume. Robust, modular, expandable architecture. …and finally the GLAST testbeams. mini-CAL to Ganil, CERN, and GSI in 2003 significant re-write: GlastAcq and GlastView in C++ and ROOT. even more modular

3. GLAST LAT Project CERN Testbeam WorkShop, Pisa, 20 March 2006 David Smith & Denis Dumora VME DAQ 3

4. GLAST LAT Project CERN Testbeam WorkShop, Pisa, 20 March 2006 David Smith & Denis Dumora VME DAQ 4 Trigger interrupts, and data formats The CIO32 is an “Industry Pack” daughter card. We have another one for RS-232 serial connections, if you like.

5. GLAST LAT Project CERN Testbeam WorkShop, Pisa, 20 March 2006 David Smith & Denis Dumora VME DAQ 5 Speed In CELESTE, we typically read 20 bunches of 128 bytes each from ten VME cards from 3 VME crates in under 10 ms. That is, 20*128b/10 ms = 256 kb/s Triggering 256 kb events at 20 Hz gave us 20Hz*0.01=20% deadtime. At CERN 2003, we had ~ 7*32*1.5b*400 Hz = 134 kb/s (we could have gone faster…) At GSI, CAL EM set the readout cadence, with Bordeaux DAQ following. Above means “better than 1 per 700  sec”.

6. GLAST LAT Project CERN Testbeam WorkShop, Pisa, 20 March 2006 David Smith & Denis Dumora VME DAQ 6 Modular Software architecture If you add a new VME card to the system, you have to write a new routine here Names of some CAEN VME modules we’ve used. (Little text files describing current setup)

7. GLAST LAT Project CERN Testbeam WorkShop, Pisa, 20 March 2006 David Smith & Denis Dumora VME DAQ 7 Mobilnet (1 of 2) Problem: folks show up with computers at the darnedest times, and the computer division isn’t necessarily ready to register their MAC numbers. Solution: a dedicated PC+router, housed in a 19-inch 3U rack box, with 7 output ports. Local administrators only see one MAC number… At CERN 2003, we plugged a switch into it and had our own little Internet Café of folks looking at data on their laptops. 40 connections is easy, more could be done.

8. GLAST LAT Project CERN Testbeam WorkShop, Pisa, 20 March 2006 David Smith & Denis Dumora VME DAQ 8 Mobilnet (2 of 2)

9. GLAST LAT Project CERN Testbeam WorkShop, Pisa, 20 March 2006 David Smith & Denis Dumora VME DAQ 9 Conclusions We have a tried & true VME-based data acquisition system with a comfortable protocol for data & command exchange with remote computers, e.g. “run control console”. On the remote computers, we have a ROOT event display and online monitor, all in C++. We have an ADC and some discriminator+scaler pairs. Some development necessary once specific needs defined. Let’s talk about testbeam needs for ancillary DAQ… We’ll bring the “mobilnet” to ease network access.